dr ltimeter / ( ) 5826 99 954 2879 117? de by () in 1966 everse engineered 1 july 2014
ht is it his rdr trnsmitter/receiver is distnce meter or ltimeter, bsed on the principle. I don't hve n instrument to mesure the frequency nd power, but I guess it is in the 4.24.4 Gz rnge. he trnsmitter is hermeticlly closed cvity, probbly with Gunn or Imptt diode s power oscilltor, tuned with vrctor. he oscilltor supply is 30dc t 250m., so the output might be pprox. 50m he trnsmitter is frequencymodulted with 300z tringle in one of 3 modes: 1. ximum mplitude is selected for low ltitude, 2 ontrolled mplitude t higher ltitude ( bove 200 feet?) 3. ithering superimposes 37.5z sinewvelike signl on the 300z tringle he receiver hs mixer with prt of the trnsmitter signl s O. he "I" mplifier hs bndwidth of 1... kz. he output of the unit is voltge, proportionl to the rnge. he unit is built in 1965 by in the nited ingdom. echnology of 1965 ypicl is the use of the very first integrted circuits in originl fltpk : first opmps from exs Instruments ( 523 en 524) first opmps from irchild ( u702 in fltpk) first digitl I's from exs Instruments ( 511 ) first digitl I's from otorol (253G) 4.3Gz oscilltor with Gunn or Imptt diode? ( just possible in 1965) trnge: he power supply hs missing diode in ech diodebridge odules dr / 5826 99 954 2879 rnsmitter I5024 estern icrowve Inc. eceiver I5023 estern icrowve Inc. hssis 5826 99 954 2870 lectronics 5826 99 954 2875 mplifier 5826 99 954 2884 sweep & control 5826 99 954 2871 deglitcher 5826 99 954 ely module 5826 99 954 2877 ower upply 6130 99 854 2869 lso from in pressurized cse: 30201 /
heory dr ltimeters with the principle hve smll trnsmitter which trnsmits continuous, frequency modulted wve. he modultion is symmetricl tringulr wve with pektopek devition () of pprox. 150z, nd frequency of 300z (=1.667 ms) he receiver receives the ground echo with second ntenn. he echo hs the trnsmitted frequency of few microseconds go, nd is mixed with the ctul trnsmitted signl. he frequency difference is proportionl with the ltitude. = pektopek frequency devition ( z) = min to mx frequency devition time, (1.667 ms) d = frequency difference between received nd trnsmitted signl; c = speed of light ( 3. ^ 8 m/s = 983 feet / µs) gives 2 x ltitude = c x d x / wice the height of the ntenn's bove the ground plus the length of the cbles to the ntenn's should be subtrcted from this vlue. y this is o [feet], nd with d in kz nd in z, this formul reduces to ltitude [feet] = 820 x d/ o his set hs fixed tringle mplitude (=) up to d=32kz from the receiver, then the bndwidth is grdully reduced down to fctor 5 t d=63kz. he reltion of the output voltge to ltitude becomes nonliner. he bet frequency mplifier hs bndwidth of 3 kz. hen I ssume o= 60 feet ( 20 meters) nd the initil is z, then he lowest frequency is 7.3 kz t 0 feet he ltitude t 32 kz is 202 feet he ltitude t 63 kz nd =/5 is 2520 feet he "vlid" rely output is ctive from d= 5 to 70 kz. with 5m input to the mplifier, or from 8 to kz with 2 m input. dr ltimeters operte in the 4200 4400 z "" bnd. oppler shift If the ltitude increses, the echo frequency rises both in the up, nd downwrd prt of the tringle, so the difference frequency is smller in the upwrd prt, nd higher in the downwrd prt of the tringle. If the modulting wve is symmetricl, nd perfectly liner, these effects verge out, nd true ltitude is mesured, independent of doppler shift when the ltitude chnges. hen the ltitude chnges with m/sec, the doppler shift is m/s x 4.2Gz/c= 140 z ypicl ltimeters dr ltimeters exist with mximum ltitude 2,500 or 5,000 ft, he circulr disply is liner up to 500 feet nd logrithmic from 500 2,500 (or 5,000) feet, mking the lower rnge of heights esier to red. ll rdio ltimeter displys hve setting control for decision height, t which point wrning will be given. he height cn be set by positioning n outside cursor ginst the required height on the scle. he setting control will normlly double s (presstotest) fcility which, when engged, drives the disply to predetermined vlue normlly feet.
esuring results he bet frequency mplifier hs reltively flt gin from 5 to kz. ith open nd inputs, squre wve of 3mpp on the connector is sufficient for stble, symmetricl squre wve to the deglitcher. 9 8 7 6 5 4 3 G (pin of mplifier) 2 1 0 0 5 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 5 1 kz he output t pin of the min connector is proportionl with the bet frequency t 80 m/kz without lod. ith 270 deg, 1m meter with 5k totl resistnce, full scle is t he "zero" position of the pointer is msked. he pointer ppers t 0 feet when d=7 kz p to 32 kz, the bndwidth is z, nd the ltitude is proportionl with the betfrequency. bove 32 kz, the is reduced (pin of min connector), nd the ltitude scle becomes non liner. he lid relys 345 re on from 5 to 75 kz. with only 2m signl (5m below z) to connector elow 32 kz, 37.5z sinewve is superimposed on the frequency modulting 300z tringle to give some dithering. he occupied bndwidth is 150z ( z without dithering)
estpoints he dr rnsmitter/eceiver hs 32 pin min plug nd 26pin testplug. he 26 pin test connector hs the following signls. ins,,,, G, nd re supply voltges 70 pwr supply vrctor diode 12 pwr supply opmps pwr supply opmps 30 pwr supply gunn diode supply gnd 21 G signl? G 0.4 pwr supply offset selftest module selftest module df/dt slope 3.5 lid rely 345 coil > 3=I wr O when connected to 115c O 32 pwr supply totempoles 31 vrctor drive signl (300z tringle) 25 pwr supply relys 115 c O 115 c I 115c on trnsformer no pin 0.. min output no pin Y disble dithering Z to min connector pin no pin b 28c from trnsformer c to min connector pin
Internl wiring j 115~ 400z x eter pwr on test? osc 25 b 1 1 2 2 ours 25 30 70 ower upply, 32 25 12 0,.c b d Y 4.3 Gz Z h rnsmitter df/dt slope b c Oscilltor selftest module? 4 5 3 ricp linerizer 12 12 30 4 5 Y 32? 25 0 32 12 12 weep genertor 600z osc. shpe :8 :2 ~ 20 ʃ d ʃ 3 1 Z slope dither off Y 18 rect 19? ontrol 1 c Z G f g G O 25 12 12 eceiver, detectors I mplifier G, / converter ltitude output 12 25 12 12 I connector est connector ire number cox 26 96 28 eglitcher one shot / conv 27 97 I 25 june 2014 kb
I II 9 front end 56k 2 0.u 8 0.u 0.u 0.u 0.u 5.9 390p.5 1 4.7u k k u702 12 150k 6.3 12 8 when in < 2pp * when in > 2pp when in < 20mpp * else 56 k 470 12 56k k 47u 8 3 1u k 56 47k 4 blue opmp u702 fltpk yellow opmp 524 or 92 56k 12 150k 8 cox 26 11 9 390p I frontend 8 k 56 n 1u 2930 12 150k k *) z squre wve on input, other inputs open 2930 484 k 47k 12 k 2u u 2 cox 27 8k2 1u 32 25 560 560 13 500 12 33u cox 28 80m / kz G 25 470k 9 25k k 8 5k 11 8 0 25k 560 7051 12 2x u 47k 390p 8k2 82 560 470k k 0 820 68k 64 2.2u 2.2u 12 23302 0k OO 12 25 17 5 2 3121 k 0k 25 d Z blue opmp 523 yellow opmps 524 k 33k 6k8 6k8 8 cox 28 Y 12 0.47 6 2.2 6.8u 2k 7 2k7 k 25 0k 33k 6k8 to chssis interconnect testpoint 1u 2.2u 1u 12 n/c k 12 6k8,,, 12 18 19 32 25 12 0 12 elfest module? G Z h 53
32 25 cox 26 cox 28 2 3 3.3u u 47 2 18n 12 17 2k4 1% 2k 47 2 33u 12 5 33n 12 n 98 33 270 12 16 4 0.1/ kz 97 8 12 trig 470 33k 15 input 26 6 cox 27 7 7 150k 150k 643 33n 14 50k 6 7 reset 96 9 47k 56k 3n3 369 4700 p 5% Glitch ilter ord on rer end of chssis o input I mplifier g 24k n 2k4 n 2k4 24k ll 1% k 23045 n n 600 z 0k 330 25 23051 2 0k 12 n k 330p k 47 n 5 23051 n 4.7u n n 1u 390p 12 12 600z 7pp 47k 5 12 560 37.5z 8pp re 2x 511 * k * 5 390p 12 blue opmp 523 (98) yellow opmp 524 (92) 50 c/s O 5 18 0 dithering on/off 300z 6pp 330p 19 20 38 2 25k 12 re 1 * 180k 180k 12 4x 511 k 37.5z 1pp 470k * 47n k 470k 0.1u * 25k k 3 300z 6pp * k u 12 6k8 68 0.47u 1u 4 to vricp
115 ~ 70 15000 thermostt 3 23497 2719 23440 167 Ω 4k 23584 4k 2k 1 7 40k 40k n 40k t Gunn? osciltor 42004400 z 30 O 50 253G x nt 12 2k 29k 33k 75 75 55 50 Y b c d Z 19 21 25 24 27 17 18 16 5 4 3 20 25 2 180k 24 2020 4 5 23 15 12 2x 2.5u 13 2 3 4k 9 4 1 1 1 9k 1 5 2 11 2 32 3 6 56n b Y d 470 Z c 7 8
0.4 2.7 Ω 2025 38 f 27 12 35 86u 24 24 680 17 2k7 1 38u shunt in trnsmitter module 13 33 20 14 30 30 70 29 35 54 2x 14u 125 24 24 5k 330 5 3.6 u >81 400z 0 hours 36 40 2.2 Ω 20 8k2 24 2025 8 39 32 unstb 27 35 25 c 24 not used 19 31 42 41 15 9 15 16 21 86u 3.3 Ω 86u 8 12 643 24 2025 2997 24 2 2k7 3 38u 19 38u 12 not mounted ire numbers in blue 24 25 15 3.3 Ω 86u 2025 330 24 24 2k7 4 37 38u oltges (c / dc) in red t 81/400z on primry when ll regultors hve stbilized output. 26